Author

Publisher

International Whaling Commission

Publication Year

2018

Abstract

Satellite transmitters were deployed on nine southern right whales (Eubalaena australis) in Golfo San Matías, Province of Rio Negro, Argentina in October 2016 (n=1) and September 2017 (n=8). This region is located nearly 200 km north of Peninsula Valdés (PV), the main breeding and calving ground for this species in the western South Atlantic Ocean. Tag duration varied between 46 and 204 days (average of 117 days). Movement patterns showed marked individual variation. Five individuals moved southwards towards Golfo San José and Golfo Nuevo, in PV shortly after tagging. Four other whales moved north along the coast of the Buenos Aires Province in Argentina and of Uruguay. Movement patterns in coastal areas suggest that whales in the northern Golfo San Matías regularly visit areas further to the south in PV, but interestingly only whales tagged in the former migrated northward along the coast. All whales eventually moved east towards offshore waters of the outer continental shelf and shelf break along the coast of Argentina (from the La Plata River to the Falkland/Malvinas Islands). Most whales tracked until later in the season (after January) migrated east/southeast towards South Georgia/Islas Georgia del Sur and the Scotia Sea/Mar de Escocia, where they remained for the duration of their tags. One individual was migrating east past 22oW of longitude when the tag stopped transmitting. Behavioral states estimated by a hierarchical space-state model indicate areas of potential foraging importance in the outer continental shelf off southern South America, the South Atlantic Basin, the Eastern Scotia Sea/Mar de Escocia and the northern Weddell Sea/Mar de Weddell. These findings complements others from an ongoing long-term study to understand the migratory routes and destinations of southern right whales wintering off the coast of Argentina and, overall, reveals that this species inhabits vast extensions of the South Atlantic Ocean and visits multiple potential feeding areas each season.